A novel wideband fractal‐shaped MIMO antenna for brain and skin implantable biomedical applications

Abstract

Summary A novel fractal‐shaped wideband multiple‐input multiple‐output (MIMO) antenna is proposed for brain and skin implantable applications. This antenna works in the 2.4–2.48 GHz band of industrial, scientific, and medical (ISM) standards. The fractal‐shaped wideband MIMO antenna is miniature in size with a footprint of 0.25em0.13normalλ×0.06normalλ×0.01normalλ. Rogers RT/Duroid 6010 high‐dielectric substrate material is used to fabricate the optimized design in order to validate the implantable MIMO antenna structure. The same high‐permittivity substrate material has been used as a superstrate. Experiments were carried out in brain and skin‐mimicking gel at 2.45 GHz in the ISM band. The proposed antenna has a peak gain of −21.3 dBi at 2.45 GHz. High isolation (>20 dB) between two MIMO ports is attained. The proposed antenna achieves a fractional bandwidth of 36.76% and an impedance bandwidth of 1.02 GHz. According to IEEE safety regulations for 1‐ and 10‐g tissues, the computed maximum specific absorption rate (SAR) is safe bound.